A common display on the market is the Thin Film transistors (TFT) liquid crystal display. Each pixel dot in the TFT liquid crystal display comprises at least one TFT and one layer of liquid crystal material. The twist of liquid crystal molecules is controlled with the on and off of the TFT to change the transmittance of the liquid crystal molecules.
In each pixel, the two ends of the liquid crystal material layer are respectively coupled to one end of the TFT and the input end of the liquid crystal drive reference voltage VCOM. When a voltage exists between the two ends of the liquid crystal layer, i.e. the voltage levels between the aforesaid one end of the TFT and the input end of the VCOM are not consistent, the liquid crystal layer may be slightly or completely pervious to light. The corresponding pixel will possess certain brightness or light up completely; on the contrary, as the voltage levels at the two ends of the liquid crystal layer are consistent, the liquid crystal layer is opaque and the corresponding pixel does not display. The on or off of the TFT is controlled by the gate voltage VG of the TFT. The gate voltage VG is commonly generated by VAA voltage of the power source input end being charged or discharged with a charge pump. The VCOM is generally obtained by dividing the VAA voltage.
In prior arts, as the liquid crystal display powers on and with the hysteretic nature of the charge pump, the rising of VG lags behind the rising of VCOM. After VCOM has already risen up in stabilization, VG temporarily remains to be at low voltage level. The liquid crystal layer will be slightly pervious to light due to the voltage existing at the two ends. The back light source is lightened up later. Before the display powers on successfully, the ambient light makes the liquid crystal display appear to be in a gleaming state because the liquid crystal layer is slightly pervious to light. Such gleaming state can easily make the user misunderstand that the display may have quality issue or malfunction happens. It does not merely affect the user's experience and even influences the production sales of the displays.